Recently, generation of noise from a vehicle provided with an internal combustion engine has been legally restricted in that the noise level is to be suppressed below a predetermined limit. The noise is partly caused by the operation of the cooling fan apparatus of the engine. The noise level generated from the fan corresponds to the rotational speed of the fan, while the speed of the fan corresponds to the cooling effect by a radiator core of the engine. Therefore, the rotational speed of the fan apparatus, in other words, the amount of air to be passed through the radiator core should be determined so that the noise is kept below a predetermined maximum level while the engine is effectively cooled.
In a conventional internal combustion engine, a fan shroud of tubular shape covering the fan assembly is arranged to face the radiator core for guiding the flow of air so that the flow is effectively passed through the radiator core. From the point of view of obtaining the maximum effect of the fan shroud, a fan shroud of a diameter conforming to the height of the radiator core should be used. However, parts for forming the engine and the vehicle body are made as module elements of standard size. Therefore, in a particular design of an engine or engine body, the fan shroud is often situated so that upper portion thereof is located above the level of the radiator core.